100+ Google Interview Questions and Answers for Freshers

Determine the minimum time required to paint all boards with given constraints.

• Use binary search to find the minimum and maximum possible time to paint all boards.

• Iterate through the boards and assign them to painters based on the time constraints.

• Calculate the total time taken to paint all boards with the assigned painters.

Count the total number of special numbers within a given range by rotating digits 180 degrees.

• Create a function to check if a number is a special number by rotating its digits.

• Iterate through the range from 1 to MAXVAL and count the special numbers.

• Handle the digit rotation mapping for 0, 1, 6, 8, 9.

• Return the count of special numbers for each test case.

Distribute chocolates among students to minimize the difference between the largest and smallest number of chocolates.

• Sort the array of chocolates.

• Use sliding window technique to find the minimum difference between the largest and smallest number of chocolates.

• Return the minimum difference as the output.

Write a select statement to retrieve work of all users who belong to my team.

• Join USERS and WORK tables on user_id

• Join MANAGERS and USERS tables on team

• Filter by manager_id

Find minimum and maximum cost to purchase all candies with special offer of free candies.

• Iterate through the candy costs array and sort it in ascending order.

• For minimum cost, start from the lowest cost candy and take free candies until reaching the next higher cost candy.

• For maximum cost, start from the highest cost candy and take free candies until reaching the next lower cost candy.

Given an array of integers and an integer K, minimize the difference between the maximum and minimum elements after adjusting each element by +/- K.

• Sort the array in non-decreasing order.

• For each element, calculate the difference between the current element and the next element.

• Adjust the element by adding or subtracting K to minimize the difference.

• Return the minimum possible difference between the maximum and minimum elements.

Calculate the number of ways Preeti can purchase items within budget, considering distinct ways.

• Use dynamic programming to calculate the number of ways to purchase items within budget

• Consider different scenarios where Preeti buys different quantities of each item

• Return the result modulo 10^9 + 7 to handle large answers

Find the water cell farthest from land in a binary matrix using Manhattan distance.

• Iterate through the matrix to find all land cells and water cells

• Calculate the Manhattan distance of each water cell to the nearest land cell

• Return the maximum distance found

Find all the bridges in an undirected graph.

• Use Tarjan's algorithm to find bridges in the graph.

• A bridge is an edge whose removal increases the number of connected components.

• Check for bridges by removing each edge and checking the number of connected components.

• Return the edges that are bridges in non-decreasing order.

Given constraints, find max vaccines administered on a specific day during a vaccination drive.

• Iterate through each test case and calculate the maximum number of vaccines distributed on the specified day.

• Distribute vaccines evenly across days while maximizing the number on the specified day.

• Ensure that the sum of vaccines administered does not exceed the maximum allowed.

• Consider edge cases like when the number of days is equal to the maximum number of vaccines available.

Given a sorted alien dictionary, determine the character order of the alien language.

• Create a graph data structure to represent the relationships between characters based on the given dictionary.

• Perform a topological sort on the graph to determine the character order of the alien language.

• Return the character array obtained from the topological sort as the final output.

Count the number of distinct ways to climb to the Nth stair by climbing one or two steps at a time.

• Use dynamic programming to solve the problem efficiently.

• The number of ways to reach the Nth stair is the sum of the number of ways to reach the (N-1)th stair and the (N-2)th stair.

• Handle base cases where N=0 and N=1 separately.

• Apply modulo 10^9+7 to avoid overflow in the final result.

Determine the minimum length of instruction sequence for a robot to reach a given target on an infinite number line.

• Start at position 0 with speed +1, update position and speed based on 'A' and 'R' instructions

• For each test case, find the shortest sequence of instructions to reach the target

• Consider both positive and negative positions for the robot

Find the maximum sum of absolute differences between adjacent elements in a circular array by rearranging the elements.

• Sort the array in non-decreasing order.

• Alternate between picking the smallest and largest elements to maximize the sum of absolute differences.

• Calculate the sum of absolute differences between adjacent elements in the rearranged array.

Multiple data structures are used to print nodes in a specific order. One data structure cannot be used alone.

• The given order suggests a depth-first search traversal of a tree-like structure.

• A stack can be used to keep track of the nodes to be visited.

• A queue can be used to store the children of a node in the order they are visited.

• An array can be used to store the nodes in the required order.

• A linked list can be used to connect the nodes in the required order.

• Using just one ...read more

Connect ropes with minimum cost by merging two smallest ropes at a time.

• Sort the array of rope lengths in ascending order.

• Merge the two smallest ropes at a time and update the cost.

• Repeat until all ropes are merged into one.

• Return the total cost as the minimum cost to connect all ropes.

Designing Google Suggest system

• I would start by analyzing user search patterns and frequently searched keywords

• Then, I would create a database of these keywords and their associated search results

• I would use indexing services to quickly retrieve relevant results for each keyword

• I would also implement machine learning algorithms to improve the accuracy of suggestions over time

Find largest pen using minimum comparisons with tops.

• Divide pens into two groups and compare largest pen from each group with largest top.

• Repeat the process with the group containing the largest pen until only one pen is left.

• The remaining pen is the largest pen.

• Total number of comparisons required is 2n-3.

Check if a number is a power of 2 and odd.

• To check if a number is a power of 2, use bitwise AND operator with the number and its predecessor. If the result is 0, it is a power of 2.

• To check if a number is odd, use modulus operator with 2. If the result is 1, it is odd.

• Example code in Python:

• def is_power_of_two(num):

• return num & (num - 1) == 0

• def is_odd(num):

• return num % 2 == 1

Algorithm to find 2 numbers in an array whose sum is equal to a target integer

• Use a hash table to store the difference between target and each element in the array

• Iterate through the array and check if the current element exists in the hash table

• Return the pair of elements that sum up to the target integer

Given n dice with 'a' sides and sum b, return no. of ways to obtain b. Optimize time and space complexity.

• Use dynamic programming to reduce time complexity

• Create a 2D array to store the number of ways to obtain each sum for each number of dice

• Use rolling arrays to optimize space complexity

• Example: n=2, a=6, b=7 -> 6 ways to obtain sum 7

• Example: n=3, a=4, b=8 -> 21 ways to obtain sum 8

Hashtable is faster for finding an item than a sorted list.

• Hashtable has constant time complexity O(1) for finding an item.

• Sorted list has logarithmic time complexity O(log n) for finding an item.

• Hashtable uses hashing to directly access the item's location.

• Sorted list requires binary search to find the item's location.

• Hashtable is ideal for large datasets with frequent lookups.

• Sorted list is ideal for datasets that require frequent insertions and deletions.

Sort 128 GB data on 2 machines with 64 GB RAM each. Extend to 1000 machines.

• Use external sorting algorithm like merge sort or quick sort

• Divide data into smaller chunks and sort them individually

• Merge sorted chunks using additional RAM

• For 1000 machines, use distributed sorting algorithms like MapReduce or Hadoop

• Ensure data consistency and fault tolerance in distributed sorting

Reviewing 30 million ads from 42 languages in Google AdWords and rejecting non-compliant ads requires a systematic approach.

• Create a set of specific rules and guidelines for ad compliance

• Use automated tools to filter out ads that violate the rules

• Assign a team of reviewers to manually check the remaining ads

• Ensure that the reviewers are fluent in the languages of the ads they are reviewing

• Regularly update the rules and guidelines to keep up with changes in the industry

• Provide...read more

Use a script to iterate through each HTML page, locate phone numbers, and update their format.

• Write a script using a programming language like Python or JavaScript to iterate through each HTML page

• Use regular expressions to locate phone numbers in the pages

• Update the format of the phone numbers as needed (e.g. adding country code, changing separators)

• Save the updated HTML pages with the new phone number format

JSON and XML are the most popular data interchange formats when using APIs.

• JSON (JavaScript Object Notation) is a lightweight format that is easy to read and write. It is widely used in web APIs.

• XML (Extensible Markup Language) is a more complex format that is also widely used in web APIs.

• Other formats include CSV (Comma Separated Values), YAML (YAML Ain't Markup Language), and Protocol Buffers.

ArrayList is preferred for frequent retrieval operations, while LinkedList is suitable for frequent insertions/deletions.

• Use ArrayList when you need fast random access and retrieval operations, such as searching for elements in a list.

• Choose LinkedList when you need fast insertions/deletions, especially at the beginning or end of the list.

• Consider memory overhead and performance trade-offs when deciding between ArrayList and LinkedList.

• For example, if you have a list of stude...read more

ReentrantLock should be used instead of synchronized when more flexibility and control over locking mechanisms is needed.

• Use ReentrantLock when you need to implement custom locking strategies or require advanced features like tryLock() and lockInterruptibly()

• ReentrantLock supports fair locking mechanisms, ensuring that threads acquire the lock in the order they requested it

• ReentrantLock allows for more fine-grained control over locking and unlocking, reducing the chances of d...read more

In Java, == checks for reference equality while equals() checks for value equality. Misuse of == can lead to logical errors.

• Override equals() when you want to compare the actual content of objects in user-defined classes.

• Override hashCode() alongside equals() to ensure consistent behavior in hash-based collections.

• Implement Comparable interface and override compareTo() for natural ordering of objects.

Garbage collection in Java automatically reclaims memory occupied by unused objects using different algorithms and memory regions.

• Force garbage collection in Java using System.gc() or Runtime.getRuntime().gc()

• Not recommended to force garbage collection as it can cause performance issues and disrupt the JVM's optimization

• Example: System.gc();

Lambda expressions in Java 8 improve readability and maintainability by allowing concise and functional-style programming.

• Lambda expressions reduce boilerplate code by providing a more compact syntax for implementing functional interfaces.

• They make code more readable by focusing on the behavior being passed as an argument, rather than the mechanics of how it is implemented.

• Lambda expressions enable developers to write more modular and reusable code, leading to better maintain...read more

By introducing new menu items, optimizing pricing strategy, and improving the overall dining experience.

• Conduct a survey to understand the preferences of employees

• Introduce healthy and affordable meal options

• Offer discounts for bulk orders or loyalty programs

• Partner with local vendors to source fresh ingredients

• Improve the ambiance and seating arrangements

• Implement online ordering and delivery services

Popular APIs for Social Commerce services

• Facebook Graph API for social media integration

• Instagram API for photo sharing and tagging

• Twitter API for real-time updates and customer engagement

• Pinterest API for product discovery and sharing

• Google Maps API for location-based services

• PayPal API for secure payment processing

Software engineering is the process of designing, developing, testing, and maintaining software.

• It involves using engineering principles to create high-quality software

• It includes various stages such as requirements gathering, design, coding, testing, and maintenance

• Theoretical knowledge includes understanding of algorithms, data structures, programming languages, and software design patterns

• Examples of software engineering practices include Agile, Waterfall, and DevOps metho...read more

ArrayList and LinkedList are both classes in Java that implement the List interface, but they have different underlying data structures.

• ArrayList uses a dynamic array to store elements, providing fast random access but slower insertion and deletion.

• LinkedList uses a doubly linked list to store elements, providing fast insertion and deletion but slower random access.

• Choose ArrayList when you need fast random access and know the size of the list beforehand. Choose LinkedList wh...read more

Java Stream is a sequence of elements that supports functional-style operations. It differs from Iterator by allowing for more concise and declarative code.

• Streams can process elements in a collection in a declarative way, allowing for functional-style operations like map, filter, and reduce.

• Streams do not store elements, they operate on the source data structure (e.g., List) directly.

• Iterators are used to iterate over a collection sequentially, while Streams can perform para...read more

Immutability in Java means objects cannot be modified after creation. String class achieves immutability by not allowing changes to its value.

• Immutability means once an object is created, its state cannot be changed.

• String class achieves immutability by making its value final and not providing any methods to modify it.

• Advantages of immutable objects include thread safety, caching, and easier debugging.

• Example: String str = "Hello"; str.concat(" World"); // This does not chang...read more

final, finally, and finalize have different meanings in Java.

• final is a keyword used to declare constants, immutable variables, or prevent method overriding.

• finally is a block used in exception handling to execute code after try-catch block.

• finalize is a method used for cleanup operations before an object is garbage collected.

Singleton design pattern ensures a class has only one instance and provides a global point of access to it.

• Create a private static instance of the class.

• Provide a public static method to access the instance.

• Use synchronized keyword or double-checked locking to ensure thread safety.

Method overloading is when multiple methods have the same name but different parameters, while method overriding is when a subclass provides a specific implementation of a method in its superclass.

• Method overloading is achieved within the same class by having multiple methods with the same name but different parameters.

• Method overriding occurs in a subclass that provides a specific implementation of a method that is already provided by its superclass.

• Method overloading is use...read more

Java annotations are metadata that provide data about a program but do not affect the program itself. They are used in frameworks like Spring to configure and customize behavior.

• Java annotations are used to provide metadata about a program, such as information about classes, methods, or fields.

• In frameworks like Spring, annotations are used to configure various aspects of the application, such as defining beans, handling transactions, or mapping URLs.

• Built-in annotations in J...read more

Using synchronized keyword for thread synchronization in Java has advantages like simplicity and disadvantages like potential for deadlock. ReentrantLock offers more flexibility and control.

• Advantages of synchronized keyword: simplicity, built-in support in Java

• Disadvantages of synchronized keyword: potential for deadlock, lack of flexibility

• ReentrantLock offers more control over locking, ability to try and lock with timeout, ability to create fair locks

• ReentrantLock can be u...read more

The Java garbage collector is responsible for automatically managing memory by reclaiming unused objects.

• The garbage collector in Java runs in the background and automatically reclaims memory from objects that are no longer in use.

• There are different types of garbage collection algorithms in Java, such as Serial, Parallel, CMS, G1, and ZGC.

• Each garbage collection algorithm has its own characteristics and is suitable for different types of applications and workloads.

The Java Memory Model defines how threads interact through memory and how synchronization ensures data consistency.

• Java Memory Model specifies how threads interact with memory, ensuring data consistency

• It defines rules for reading and writing shared variables in a multithreaded environment

• Synchronization mechanisms like synchronized blocks and locks ensure proper visibility and ordering of memory operations

• The 'volatile' keyword in Java ensures that changes made by one thread...read more

Java Streams handle parallel processing by splitting the data into multiple chunks and processing them concurrently.

• Java Streams use the Fork/Join framework to split the data into chunks and process them in parallel.

• Potential pitfalls include increased overhead due to thread management, potential race conditions, and decreased performance for small datasets.

• Pitfalls can be mitigated by ensuring thread safety, avoiding stateful operations, and testing performance with differen...read more

In Java, == compares memory addresses while .equals() compares values of objects. Improper usage can lead to unexpected results.

• Use == to compare primitive data types or check if two objects reference the same memory address.

• Use .equals() to compare the values of objects, such as strings or custom classes.

• Improper usage of == with objects can lead to unexpected results as it compares memory addresses, not values.

Java 8 introduced features like lambdas and Stream API which have revolutionized the way Java applications are written.

• Lambdas allow for more concise and readable code by enabling functional programming paradigms.

• Stream API provides a way to process collections of objects in a functional style, making code more expressive and efficient.

• Java 8 also introduced default methods in interfaces, allowing for backward compatibility without breaking existing code.

• The new Date and Time...read more

Functional interfaces in Java are interfaces with a single abstract method. They can be used with lambda expressions for functional programming.

• Functional interfaces have only one abstract method, but can have multiple default or static methods.

• Lambda expressions can be used to implement the abstract method of a functional interface concisely.

• An example of a custom functional interface is 'Calculator' with a single abstract method 'calculate'.

Checked exceptions are checked at compile time, while unchecked exceptions are not. Proper handling involves either catching or declaring the exception.

• Checked exceptions must be either caught or declared in the method signature using the 'throws' keyword.

• Unchecked exceptions do not need to be caught or declared, but can still be handled using try-catch blocks.

• Examples of checked exceptions include IOException and ClassNotFoundException, while examples of unchecked exceptions...read more

Given a sequence of room bookings and freeings, find the room that is booked the most times.

• Create a hashmap to store the count of each room booking.

• Iterate through the sequence of bookings and freeings, updating the count in the hashmap.

• Find the room with the highest count and return it. In case of a tie, return the lexicographically smaller room.

• Example: For input n = 6, Arr[] = {"+1A", "+3E", "-1A", "+4F", "+1A", "-3E"}, the output would be "1A".

DSA stands for Data Structures and Algorithms. It is essential for efficient problem-solving in software development.

• DSA helps in organizing and managing data effectively

• It improves the efficiency and performance of algorithms

• Common data structures include arrays, linked lists, trees, graphs

• Common algorithms include sorting, searching, and dynamic programming

C++ is a programming language used for developing software applications.

• C++ is a high-level programming language known for its performance and flexibility.

• It is commonly used for developing system software, game engines, and applications that require high performance.

• C++ supports object-oriented programming, generic programming, and low-level memory manipulation.

• Examples of software developed using C++ include operating systems like Windows, game engines like Unreal Engine, a...read more

Java is a popular programming language used for developing a wide range of applications.

• Java is platform-independent, meaning it can run on any device with a Java Virtual Machine (JVM)

• It is used for developing web applications, mobile apps, desktop applications, and enterprise software

• Java is known for its security features and scalability

• Examples of Java-based applications include Android apps, online banking systems, and e-commerce websites

Spring is a popular Java framework for building web applications and microservices.

• Spring provides a comprehensive programming and configuration model for modern Java-based enterprise applications.

• It offers features like dependency injection, aspect-oriented programming, and transaction management.

• Spring Boot is a popular extension of the framework that simplifies the process of creating standalone, production-grade Spring-based applications.

• Spring is important because it hel...read more

Given an array, remove K elements from beginning or end to maximize sum of remaining elements.

• Iterate through all possible combinations of removing K elements from beginning and end

• Calculate sum of remaining elements for each combination

• Return the maximum sum obtained

Assign subjects to friends to minimize maximum workload, find minimum time for most loaded friend.

• Sort subjects in descending order

• Assign subjects to friends one by one until all subjects are assigned

• The maximum workload will be the sum of problems assigned to the friend with the most problems

• Return the maximum workload as the minimum time required

Implement a function to find the shortest path in an unweighted graph from house 'S' to house 'T'.

• Use Breadth First Search (BFS) algorithm to find the shortest path in an unweighted graph.

• Create a queue to store the current house and its neighbors, and a visited set to keep track of visited houses.

• Start BFS from house 'S' and stop when reaching house 'T'.

• Return the path from 'S' to 'T' once 'T' is reached.

• If multiple shortest paths exist, any one can be returned.

• Example: For ...read more

Calculate and print the sum of least common multiples (LCM) for each integer from 1 to N with N.

• Iterate from 1 to N and calculate LCM of each number with N

• Sum up all the calculated LCMs to get the final result

• Implement a function to calculate LCM of two numbers

Sorting an array of strings without using inbuilt methods

• Use a sorting algorithm like bubble sort, selection sort, or insertion sort

• Compare each element with the next one and swap if necessary

• Repeat the process until the array is sorted

JavaScript is a programming language used for creating interactive web pages and web applications.

• JavaScript is a high-level, interpreted language.

• It is primarily used for client-side scripting.

• JavaScript can be embedded directly into HTML pages.

• It provides dynamic functionality and interactivity to websites.

• Common uses include form validation, DOM manipulation, and AJAX requests.

Java8 is popular due to its new features like lambda expressions, streams, and functional interfaces.

• Lambda expressions provide concise code and simplify functional programming.

• Streams allow for efficient processing of large data sets.

• Functional interfaces enable the use of lambda expressions.

• Java8 also introduced new APIs like Optional and Date/Time API.

• Java8 is backward compatible with previous versions of Java.

• Java8 is widely used in enterprise applications and big data pr...read more

A linked list is a linear data structure where elements are stored in nodes that have a reference to the next node in the sequence.

• Consists of nodes connected by pointers

• Does not have a fixed size like arrays

• Allows for efficient insertion and deletion operations

• Example: Singly linked list, Doubly linked list

Find the path from a leaf node to the root node in a binary tree with the maximum sum.

• Traverse the binary tree from leaf to root while keeping track of the sum along the path.

• Compare the sums of all root-to-leaf paths and return the path with the maximum sum.

• Use recursion to traverse the tree efficiently and update the sum as you go.

• Consider edge cases like null nodes and negative values in the tree.

BFS traversal of an undirected and disconnected graph starting from vertex 0.

• Implement BFS algorithm to traverse the graph starting from vertex 0.

• Use a queue to keep track of visited nodes and their neighbors.

• Ensure to print the nodes in numerical sort order when multiple neighbors are present.

• Handle disconnected components by checking for unvisited nodes.

• Output the BFS traversal sequence for each test case in a separate line.

Dijkstra's algorithm is used to find the shortest path from a source node to all other nodes in a graph with weighted edges.

• Implement Dijkstra's algorithm to find the shortest path distances from the source node to all other nodes

• Use a priority queue to efficiently select the next node with the shortest distance

• Update the distances of neighboring nodes if a shorter path is found

• Handle disconnected vertices by assigning a large value (e.g., 2147483647) as the distance

• Ensure no...read more

Delete all leaf nodes with value X in a binary tree until no such leaves exist.

• Traverse the tree in postorder fashion to delete leaf nodes with value X

• Recursively call the function on left and right subtrees

• Update the root of the tree after removing leaf nodes with value X

Given a string representing time with some digits as '?', fill in '?' to get maximum time.

• Iterate through each digit of the input string and replace '?' with the maximum possible digit based on the position.

• For the first digit (hours), if it is '?', replace it with '2' if the second digit is also '?', else replace it with '1'.

• For the second digit (hours), if it is '?', replace it with '3' if the first digit is '2', else replace it with '9'.

• For the third digit (minutes), if it...read more

Search for integers in a rotated sorted array efficiently using binary search.

• Use binary search to efficiently find the index of each query integer in the rotated sorted array.

• Handle the rotation of the array by finding the pivot point first.

• Check which half of the array the query integer falls into based on the pivot point.

• Return the index of the query integer if found, else return -1.

Calculate sum of bit differences among all pairs in an array of integers.

• Iterate through all pairs of elements in the array

• Convert each pair of elements to binary representation

• Count the differing bits in the binary representations

• Sum up the differing bits for all pairs to get the final result

Determine the number of good quality bulbs remaining after 'N' rounds of a unique technique.

• In each round, bulbs are toggled based on their position (e.g. every second bulb, every third bulb, etc.)

• At the end of 'N' rounds, count the bulbs that remain on to determine the number of good quality bulbs.

• Example: For N = 4, bulbs 1 and 4 remain on, so the output is 2.

Given a dictionary and queries with wildcard characters, determine how many words in the dictionary can match each query.

• Iterate through each query and dictionary word to check for matches

• Replace '?' with all possible lowercase letters and compare with dictionary words

• Count the number of matches for each query

Given a singly linked list of integers and a reference to a node, delete the specified node from the linked list.

• Traverse the linked list to find the node to be deleted.

• Update the pointers to skip over the node to be deleted.

• Print the modified linked list after deletion.

• Ensure the node to be deleted is not the tail node.

Find the maximum sum of a contiguous subarray within an array of integers.

• Use Kadane's algorithm to find the maximum subarray sum efficiently.

• Initialize two variables: maxEndingHere and maxSoFar.

• Iterate through the array and update the variables accordingly.

• Return the maxSoFar as the result.

Find the size of the smallest subset with maximum OR value among all subsets of an array of positive integers.

• Iterate through all possible subsets of the array

• Calculate the OR value for each subset

• Track the size of the smallest subset with maximum OR value

The task is to find the total number of ways to make change for a specified value using given denominations.

• Use dynamic programming to solve this problem efficiently.

• Create a 2D array to store the number of ways to make change for each value up to the specified value.

• Initialize the array with base cases and then iterate through the denominations to fill up the array.

• The final answer will be in the last cell of the array.

• Example: For N=3, D=[1, 2, 3], V=4, the output should be...read more

Count distinct values obtained by applying bitwise OR operation on all possible subarrays of an array of positive integers.

• Use a set to store distinct values obtained by bitwise OR operation on all subarrays.

• Iterate through all subarrays efficiently to calculate distinct values.

• Optimize the solution to handle large input sizes efficiently.

House Robber problem - determine maximum amount of money to rob without triggering alarm in circular arrangement of houses.

• Use dynamic programming to keep track of maximum money robbed at each house.

• Consider two cases: robbing the first house and not robbing the first house.

• Handle circular arrangement by considering the first and last house separately.

• Example: For arr[] = {2, 3, 2}, the output is 3. Mr. X robs house 2.

• Example: For arr[] = {1, 2, 3, 1}, the output is 4. Mr. X ...read more

Find all possible paths for a rat in a maze to reach its destination, given a matrix representation of the maze.

• Use backtracking to explore all possible paths from the starting position to the destination.

• Keep track of the current path and explore all possible directions at each step.

• Terminate the exploration when reaching the destination and add the path to the result list.

• Sort the result list of paths in alphabetical order before returning.

The problem involves finding the maximum element in each sliding window of size 'K' in an array of integers.

• Use a deque to store indices of elements in the current window in decreasing order of their values.

• Remove indices that are out of the current window from the front of the deque.

• Add the maximum element (at the front of the deque) to the result for each window.

Validate if a binary tree is a Binary Search Tree (BST) based on given properties.

• Check if the left subtree of a node contains only nodes with data less than the node's data.

• Verify if the right subtree of a node contains only nodes with data greater than the node's data.

• Ensure that both the left and right subtrees are also binary search trees.

• Traverse the tree in level order form to validate the BST properties.

• Return true if the binary tree is a BST, otherwise return false.

Count the number of palindrome words in a given string.

• Split the string into words using whitespace as delimiter.

• Check each word if it is a palindrome by comparing it with its reverse.

• Increment a counter for each palindrome word found.

• Output the final count of palindrome words for each test case.

Implement a Sudoku solver for a 9x9 grid with constraints on row, column, and 3x3 grid.

• Create a recursive function to solve the Sudoku puzzle by trying out different numbers in empty slots.

• Use backtracking to backtrack and try different numbers if a conflict is encountered.

• Ensure each number appears only once in each row, column, and 3x3 grid.

• Implement a function to check if a number can be placed in a particular position based on Sudoku rules.

• Test the solver with different S...read more

Local variables are variables that are defined within a function and can only be accessed within that function. Global variables are variables that are defined outside of any function and can be accessed throughout the program.

• Local variables are created when a function is called and destroyed when the function completes.

• Global variables can be accessed and modified by any function in the program.

• Using local variables helps in encapsulation and prevents naming conflicts.

• Globa...read more

To increase sales or marketing figures immediately, focus on targeted advertising, offering promotions, improving customer experience, and leveraging social media.

• Implement targeted advertising campaigns to reach the right audience

• Offer promotions or discounts to attract new customers and incentivize purchases

• Improve customer experience through excellent service, personalized interactions, and efficient processes

• Leverage social media platforms to engage with customers, create...read more

There are various types of graphs used in data visualization, such as bar graphs, line graphs, pie charts, scatter plots, and histograms.

• Bar graph - used to compare different categories

• Line graph - shows trends over time

• Pie chart - displays parts of a whole

• Scatter plot - shows relationship between two variables

• Histogram - displays distribution of data

Answers to common Python interview questions.

• Namespace is a container for storing variables and functions.

• Dictionary is a collection of key-value pairs.

• Type conversion is the process of converting one data type to another.

• Arrays are homogeneous while lists are heterogeneous.

• Functions are blocks of code that perform a specific task.

Python is a high-level, interpreted programming language known for its simplicity, readability, and versatility.

• Python is used for web development, data analysis, artificial intelligence, and more.

• Advantages of Python include its ease of use, large standard library, and community support.

• Functions in Python are used to group related code and make it reusable.

• The break statement is used to exit a loop prematurely.

• A tuple is an ordered, immutable collection of elements.

Ordered map maintains the order of insertion while unordered map does not guarantee any specific order.

• Ordered map: elements are stored in the order they were inserted

• Unordered map: elements are stored in an unspecified order for faster access

• Example: std::map vs std::unordered_map in C++

Coding is the process of writing instructions in a specific programming language, while programming involves the entire process of designing, writing, testing, and maintaining code.

• Coding is the act of translating a problem into a language that a computer can understand.

• Programming involves planning, designing, implementing, and testing a solution to a problem.

• Coding is a subset of programming, focusing on the actual writing of code.

• Programming encompasses a broader range of ...read more